Apparatus for drying refrigerant

ABSTRACT

The present invention relates to improved apparatus for drying the refrigerant in refrigeration systems such as automobile air conditioners and the like. A refrigerant permeable desiccant retainer formed of a rigid impervious material having a quantity of particulated or beaded solid desiccant disposed therein is attached within a closed container. The closed container is connected in a refrigeration system downstream of the refrigerant condenser so that liquefied refrigerant passes therethrough. The desiccant retainer prevents the desiccant from escaping from the container and obviates the use of sack-type retainers formed of cloth heretofore used.

United States Patent [72] inventors Robert M. Alters;

Harold L. Westiall, both of Oklahoma City, Okla.

[21] Appl. No. 856,595

{22] Filed Sept. 10, 1969 [45] Patented Nov. 9, 1971 73] Assignee Akers, Incorporated Oklahoma City, Okla.

[54] APPARATUS FOR DRYING REFRIGERANT 1 Claim, 3 Drawing Figs.

[52] U.S. C1 210/95, 210/266, 210/288 [51] Int. Cl 801d 17/06, 801d 29/24 [50] Field of Search 210/94, 95, 131, 266, 282, 288, 440, 443

[56] References Cited UNITED STATES PATENTS 2,758,719 8/1956 Line 210/443 X 2,789,654 4/1957 Zurit 210/282 X 2,873,856 2/1959 Jones..... 210/266 X 3,064,819 11/1962 Jones 210/282 X 3,266,628 8/1966 Price 210/282 X FOREIGN PATENTS 662,016 4/1963 Canada 210/282 Primary ExaminerSamih N. Zahama Attorney-Dunlap, Laney, Hessin & Dougherty ABSTRACT: The present invention relates to improved apparatus for drying the refrigerant in refrigeration systems such as automobile air conditioners and the like. A refrigerant permeable desiccant retainer formed of a rigid impervious material having a quantity of particulated or beaded solid desiccant disposed therein is attached within a closed container. The closed container is connected in a refrigeration system downstream of the refrigerant condenser so that liquefied refrigerant passes therethrough. The desiccant retainer prevents the desiccant from escaping from the container and obviates the use of sack-type retainers formed of cloth heretofore used.

APPARATUS FOR DRYING REFRIGERANT BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates generally to improved apparatus for drying refrigerant, and more particularly, but not by way of limitation, to improved apparatus for continuously drying the refrigerant in refrigeration systems with particulated or beaded solid desiccant.

2. Description of the Prior Art Refrigerant dryers are commonly employed in refrigeration systems such as air conditioners and the like. Generally, such drying apparatus contains a quantity of solid desiccant and is installed in a refrigeration system downstream of the refrigerant condenser so that liquefied refrigerant is passed over the desiccant. As the desiccant contacts the liquid refrigerant it absorbs water therefrom thereby preventing corrosion and sludge buildup in the refrigeration system. The desiccant most commonly used for drying refrigerant is a silica gel having an affinity for water formed in small beads or particles.

l-leretofore, such apparatus for drying refrigerant has been comprised of a closed container having a refrigerant inlet connection and a refrigerant outlet connection disposed therein. A quantity of desiccant particles or beads contained within a sack formed of cloth is disposed in the container, and liquid refrigerant is contacted by the desiccant as it passes through the sack. While desiccant contained within such a sack will satisfactorily absorb water from the refrigerant passing therethrough, various problems have been encountered relating to the use of refrigerant permeable sacks formed of cloth and the like. Specifically, it has been found that rapid attrition of the sack takes place causing small pieces thereof, or lint therefrom, to be released into the refrigerant. These pieces of cloth or lint flow with the refrigerant out of the drying apparatus and find their way into other parts of the refrigeration system causing them to be damaged or plugged. Furthermore, such sacks rapidly wear out allowing the desiccant to be washed about within the drying apparatus. This in turn caused the desiccant to break up into fine particles which also escape from the apparatus into the refrigeration system causing damage thereto.

SUMMARY OF THE INVENTION The present invention relates to improved apparatus for drying refrigerant which comprises a closed cylindrical container having a refrigerant inlet connection and a refrigerant outlet connection in the top portion thereof, a feed tube connected to the refrigerant outlet connection and extending within the container to a point near the bottom thereof, and a refrigerant permeable desiccant retainer formed of a rigid impervious material having a quantity of solid desiccant disposed therein attached to said feed tube.

It is, therefore, a general object of the present invention to provide an improved apparatus for drying refrigerant.

A further object of the present invention is the provision of improved apparatus for drying refrigerant which includes a refrigerant permeable desiccant retainer formed of impervious material which will not rapidly wear out from attrition.

A further object of the present invention is the provision of improved apparatus for drying refrigerant wherein desiccant particles, lint, and other materials are prevented from being released into the refrigerant.

Other and further objects and advantages of the invention will be evident from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view, partially in section, of the improved apparatus of the present invention,

FIG. 2 is a side sectional view of the desiccant retainer of FIG. 1, and

FIG. 3 is a top plan view of the desiccant retainer of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing, and particularly FIG. 1, the improved apparatus of the present invention is generally designated by the numeral 10. The apparatus 10 basically comprises a cylindrical container 12 closed at the bottom end 14 thereof by a closure member 16 welded or otherwise sealingly attached thereto. The upper end 18 of the container 12 is closed by a closure member 20 which is welded or otherwise sealingly attached thereto. The member 20 includes a threaded inlet connection 22 for threadedly connecting a refrigerant hose or tubing 24 thereto, such as by conventional fitting 26. The threaded inlet connection 22 is connected to the internal space of the container 12 by a horizontal bore 28 which intersects a vertical bore 30 disposed in the member 20. An outlet connection 32 is disposed in the member 20 for threadedly receiving a conventional threaded fitting 34 which is in turn attached to a refrigeration hose or tubing 36. The connection 32 is connected to the internal space of the container 12 by a horizontal bore 38 which intersects a bore 40 disposed vertically through the member 20. A conventional sight glass 42 is sealingly attached to the upper end of the bore 40.

A feed tube 44 formed from a length of conduit is disposed vertically within the container 12 having the upper end 46 thereof sealingly connected in the lower end of the bore 40 of the member 20 in a conventional manner such as by welding. The lower end 48 of the feed tube 44 terminates at a point near the bottom end 14 of the container 12. A desiccant retainer 50 is slidably disposed over the feed tube 44 and positioned at a point approximately midway along the length thereof. A conventional screen member 52 is attached to the lower end 48 of the feed tube 44.

Referring now to FIG. 2, the desiccant retainer 50 is shown in cross section. The member 50 may be formed of any suitable rigid material which is impervious to refrigerants, such as Freon, commonly used in refrigeration systems. A preferred material is rigid polyvinyl chloride plastic which may be readily thermoformed into the desired shape, and which is impervious to Freon. However, other materials such as steel or other metals may be utilized.

The desiccant retainer 50 basically comprises an inner wall 54 formed in the shape of a cylinder, a perforated annular bottom member 56, a cylindrically shaped outer wall 58 and a perforated annular top member 60. As will be understood, the inner wall 54, bottom member 56 and outer wall 58 may be integrally formed from plastic material such as by the injection mold process. The space 62 defined by the inner surface of the wall 54 is formed of circular shape in cross section having a diameter at the lower end 64 thereof equal to the outside diameter of the feed tube 44, and a diameter at the upper end 66 thereof slightly less than the diameter of the feed tube 44. That is, the cross-sectional diameter of the upper end 66 of the space 62 is preferably approximately 0.005 inches smaller than the outside diameter of the feed tube 44. Thus, the desiccant retainer 50 may be readily secured on the feed tube 44 and held in position by the tight fit between the top portion 66 of the space 62 and the outside surface of the siphon 44.

The annular perforated top member 60 of the retainer 50 is removable from the retainer 50, and includes an annulet 68 extending around the lower periphery thereof for fitting relationship into an annular groove 70 formed in the inside surface of the wall 58. An annular flange 72 is provided on the top member 60 for fitting over the upper end 74 of the wall 58. Thus, once the top member 60 has been positioned on the wall 58, it is prevented from moving downwardly by the flange 72 and prevented from moving upwardly by the coaction of annulet 68 with the groove 70.

As indicated above, both the bottom member 56 and top member 60 include a plurality of perforations 76 extending vertically therethrough. The perforations 76 may be formed in any convenient shape in cross section such as the square shape shown in FIG. 3.

The annular space 78 formed between the inner wall 54 and the outer wall 58 of the retainer 50 is filled with a suitable solid desiccant 80, such as silica gel formed in beads or particles. To prevent the desiccant from passing through the perforations 76, a pair of annular felt pads 82 may be disposed adjacent to the bottom member 56 and upper member 60 as shown in FIG. 2.

OPERATION Referring now to FIG. 1, the apparatus 10 is installed in a refrigeration system, such as an automobile air conditioner, downstream of the refrigerant compressor and condenser so that a stream of liquid refrigerant enters the apparatus 10 through a hose or tubing 24 and is removed from the apparatus 10 through a hose or tubing 36. Since the refrigerant is under superatmospheric pressure, air contained within the container 12 will be compressed, and a body 84 of refrigerant liquid will accumulate in the container 12. As refrigerant is continuously circulated through the refrigeration system, it enters the container 12 through the inlet connection 22 of the member 20, passes downwardly towards the bottom 14 of the container 12, through the screen member 52, into feed tube 44 and out of the apparatus 10 through the outlet connection 32. As the refrigerant passes downwardly within the container 12, a portion thereof will pass through the apertures 76 in the top member 60 of desiccant retainer 50, through the desiccant 80 contained therein and out of the desiccant retainer 50 through the apertures 76 in the bottom member 56. Thus, water contained in the refrigerant will be absorbed by the desiccant 80, and since the refrigerant in a refrigeration system is circulated at a relatively high rate, all of the refrigerant will be contacted by the desiccant 80 after a relatively short period of time. The screen member 52 traps any dirt or other solid particles that may initially be in the refrigeration system thereby preventing it from continuously circulating with the refrigerant.

The desiccant retainer 50 is formed of a material impervi' ous to refrigerant, and thus, will not wear out or in any way contribute to the release of foreign matter in the refrigeration system. Additionally, the desiccant retainer 50 permanently retains the solid desiccant particles 80 thereby preventing them from washing about and disintegrating into smaller particles which can travel through the screen 52. Any fine particles of desiccant formed through attrition of the desiccant particles within the retainer 50 are prevented from escaping from the retainer 50 by the felt pads 82.

Thus, the improved apparatus of the present invention achieves effective drying of the refrigerant without contributing to the release of foreign materials such as pieces of cloth, lint and desiccant particles into the refrigeration system which can damage or plug the system.

The present invention, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as those inherent therein. While presently preferred embodiments of the invention are given for the purpose of disclosure, numerous changes in the details of construction and arrangement of parts can be made which will readily suggest themselves to those skilled in the art.

What is claimed is:

1. Apparatus for drying refrigerant which comprises:

a closed elongated cylindrical container having a refrigerant inlet connection and a refrigerant outlet connection in the top portion thereof;

a feed tube connected to the refrigerant outlet connection and extending within said container to a point near the bottom thereof;

a screen member attached to the lower end of said feed tube adjacent the bottom of said container;

means for viewing refrigerant from outside said container at the point of connection of said feed tube to the refrigerant outlet connection; a refrigerant permeable desiccant retainer fonned of a rigid impervious material having a quantity of solid desiccant disposed therein attached to said feed tube within said container, comprising:

a cylindrical inner wall slidably disposed on said feed tube;

a perforated annular bottom member attached to said annular wall and having an outer diameter substantially less than the inner diameter of said container;

a cylindrical outer wall attached to said bottom member and having an outer diameter substantially less than the inner diameter of said container; and

a perforated annular top member removably attached to said inner and outer walls and having an outer diameter substantially less than the inner diameter of said container; and

a pair of annular felt pads disposed within said desiccant retainer respectively adjacent the top and bottom members thereof. 

1. Apparatus for drying refrigerant which comprises: a closed elongated cylindrical container having a refrigerant inlet connection and a refrigerant outlet connection in the top portion thereof; a feed tube connected to the refrigerant outlet connection and extending within said container to a point near the bottom thereof; a screen member attached to the lower end of said feed tube adjacent the bottom of said container; means for viewing refrigerant from outside said container at the point of connection of said feed tube to the refrigerant outlet connection; a refrigerant permeable desiccant retainer formed of a rigid impervious material having a quantity of solid desiccant disposed therein attached to said feed tube within said container, comprising: a cylindrical inner wall slidably disposed on said feed tube; a perforated annular bottom member attached to said annular wall and having an outer diameter substantially less than the inner diameter of said container; a cylindrical outer wall attached to said bottom member and having an outer diameter substantially less than the inner diameter of said container; and a perforated annular top member removably attached to said inner and outer walls and having an outer diameter substantially less than the inner diameter of said container; and a pair of annular felt pads disposed within said desiccant retainer respectively adjacent the top and bottom members thereof. 